The present invention relates generally to polymeric coated support members and more particularly to support members coated with a reactive polymer for use on utility poles.
The purpose of a utility pole is to support various lines and to aide in their distribution. Some of the various lines that are supported on utility poles include telephone lines, television cables, and power or electric lines. Ideally, when supporting power lines, utility poles do not interfere with the transmission of electricity.
The top portion of a typical utility pole is represented in FIG. 1. As shown, a utility pole may include one or more crossbeams for supporting multiple lines and may further include various accessories for guiding lines and for supporting and anchoring the pole. For instance, some of these accessories may include ceramic insulators upon which the power lines rest. The ceramic insulators in turn are supported upon insulator posts that are attached to the utility pole or to a crossbeam.
Other accessories include crossbars, which can be used to support the crossbeams, and guidewires which help support the utility pole by extending from the pole to the ground. At the ground end, the guidewires are typically connected to a guidewire support which is in turn secured to a metal pin that has been driven into the ground.
Traditionally, utility poles including any crossbeams supported thereon have been made from pretreated wood. The above-described support members, including insulator posts, crossbars, and guidewires, on the other hand, have been made from metallic materials. Unfortunately, these metallic support members tend to corrode and fail over time, especially when placed in unfavorable environments. Further, being made from metal, some utility pole accessories have interfered with electrical transmissions through the lines that are supported on the pole.
For instance, in the past, insulator posts have been made from galvanized steel with a threaded portion made from lead. The lead portion is for attachment to a ceramic insulator which is placed in contact with a power line. The threaded portion must be made from a softer material in order to avoid cracking or harming the ceramic insulator during temperature swings. However, being made from a conductive metal, these insulator posts have been found to cause the supported power lines to arc-over. As used herein, an arc-over refers to an unwanted arc or discharge of electricity from a power line resulting from the breakdown of insulation. Arc-over causes a loss of electricity and a reduction in the efficiency of transmitting the electricity.
This phenomenon of arc-over of electrical lines caused by insulator posts is especially a problem for utility poles located in close proximity to large salt water bodies including oceans and salt water lakes. In particular, salt water found in the air in these regions enhances the ability for electricity to arc from the power line to the metallic posts.
Besides causing the loss of electricity in power lines, current insulator posts also pose a threat to the environment because they often contain large amounts of lead. Lead is a very toxic material that can pose some very serious health risks when present in water reserves or otherwise ingested. As such, it would be environmentally advantageous to replace the lead portion of insulator posts with a nontoxic material.
Besides causing the loss of electricity, metallic support members used on utility poles are also vulnerable to corrosion and ultimate failure. For example, the guidewires and crossbars as described above are known to rust and corrode over time. In particular, in some situations, the ends of guidewires are anchored to the ground submerged in a wet area or marsh. To prevent corrosion, plastic coatings have been applied to the wires. However, these coatings, thus far, have not proven successful in completely protecting the wires. In particular, the coatings tend to delaminate over time exposing the underlying metal.
Similar to guidewires, metallic crossbars have also been prone to corrode over time. Attempts to correct this problem have included making the crossbars out of corrosive resistant materials such as galvanized steel. However, crossbars located in wet environments still continue to corrode.
Besides guidewires and crossbars, all other metallic parts on utility poles have also been prone to failure and are subject to ultimate replacement. For instance, another major concern is the gradual corrosion of transformer boxes which are also found mounted to utility poles. As such, a need exists for replacing metallic support members used on utility poles with noncorrosive parts. Also, a need exists for utility pole accessories that do not interfere with the transmission of electricity through power lines supported on the poles. Ideally, the accessories are dielectric, meaning that the accessories can not conduct an electrical current.